The invention relates generally to breathing masks adapted to be worn on the face of a human being, and in particular to an apparatus for use with a breathing mask to transmit the wearer's voice outside the mask.
Breathing masks are well known in the prior art. Such masks are used, for example, by military jet pilots to aid them in breathing at high altitudes. A typical mask includes a generally cup-shaped main body which is made of a pliable, air impermeable material, such as rubber; and the main body is coupled to a source of an oxygen-rich breathing mixture by means of a hose, or the like. In use, the mask is worn over the nose and mouth and forms an air-tight seal with the wearer's face. In most cases, the mask is also provided with a strap which passes around the wearer's head and holds the mask in place so that the wearer can have his hands free while breathing through the mask.
In order to permit the wearer to transmit his voice outside the mask, prior art masks have included built-in microphones. Unfortunately, the introduction of a microphone into the interior environment of the mask introduces a number of problems which, until the present invention, have not been adequately solved. First of all, it is very dangerous to include an electrical device such as a microphone in an oxygen-rich environment because of the ever present danger that an electrical spark may ignite the oxygen within the mask. In addition, the oxygen-rich environment and moisture introduced from the wearer's breath may very rapidly corrode the metal parts of the microphone. Furthermore, the microphone, which senses sounds inside the mask and communicates with a point outside the mask, has always either been mounted so that it penetrates the body of the mask or has been mounted inside the mask and has included an electrical connector that penetrated the body of the mask. In either case, openings must be provided in the body of the mask, and, even if these openings can be sealed adequately when the mask is new, they often leak as the mask ages or wears with use.